In the stately hallways of Capitol Hill, where the first impeachment trial of an elected US president is under way, all is not as somber as it might seem for the senators hearing the case.

Showing off plastic strings of bright pink, green, and purple Mardi Gras beads at her desk, Senator Lincoln earlier threatened to wear them onto the Senate floor during the proceedings. "I might need to liven things up there a little today!" laughs the freshman Democrat from Arkansas.

Behind the faade of decorum, a day in the life of a Senate deliberator suggests that the trial is both an intensely public and personal event.

Compelled to sit indefinitely as a court of impeachment, Lincoln and 99 other senators are wielding what is considered one of the Senate's most awesome powers as they act both as the judges and jurors of the president.

But the rest of life hasn't stopped for the senators, many of whom, like the newly elected Lincoln - the mother of two-year-old twin boys - have had little time to prepare for this daunting role.

"That's the one thing - you have absolutely no time for yourself," says Lincoln, sitting at a desk cluttered with family photos and a jar of red, white, and blue jelly beans. "I'm still writing Christmas thank-you notes."

Lincoln readily admits that she hasn't come close to reading the 60,000 pages of evidence submitted for the trial, nor has she studied the Federalist Papers or other historic documents freshly perused by some colleagues.

Instead, her first order of business one recent morning is to call home near Hughes, Ark., to chat with her mother, her physician husband, and her boys - a constant theme in her political life.

In 1996, Lincoln announced she was pregnant with the twins and would not seek a third term in the House of Representatives. She gave birth that June. Then last year, after Sen. Dale Bumpers decided to retire, she campaigned successfully for the seat using a family-oriented platform, saying she wanted to make the country better for her children.

Today, whenever she's home she still cooks the boys' breakfast - oatmeal laden with butter and brown sugar - and tucks them in at night. The family plans soon to move to Washington, although the boys have only a vague idea why.

"Work. Mommy work," Lincoln says, mimicking toddler-ese as she heads to her next morning event: an official Senate photo.

AT THE studio, the seventh-generation Arkansan makes sure there is a state flag in the background. The youngest woman ever elected to the Senate, she follows another Arkansas pioneer. Hattie Caraway in 1932 became the first woman ever elected to the body.

Lincoln dabs on some powder and rouge, inspecting her navy blue suit for smudges. "I put on my coat the other day and it had drool on the shoulder," she sighs. She rejects the first Polaroid proofs, but after several minutes of primping her hair she smiles again at the camera.

After a closed-door Democratic Party caucus meeting and lunch with staff, Lincoln turns her attention to impeachment.

At 1 p.m. inside the Senate chamber, all rise as the robed Chief Justice William Rehnquist enters to convene the court. The chaplain delivers a prayer, calling on the senators to listen amid "the cacophony of voices" for divine guidance.

Arriving late, Lincoln slips in to take her second-to-back-row seat. Ignoring the order for silence "on pain of imprisonment," she shares a laugh with Sen. Joseph Lieberman (D) of Connecticut and gets a hug from Sen. John Kerry (D) of Massachusetts.

Looking around the room filled with attorneys-turned-senators "initially made me feel nervous," says Lincoln, who comes from a family of farmers and doctors. But upon reflection, Lincoln says her viewpoint is valuable.

"My perspective ... comes from a purely parental background," she says. "I think of the discipline and the things I want my children to learn."

Seeming more comfortable as a juror than judge, Lincoln says her priority is to listen carefully to the lengthy trial arguments. Still, she and other senators begin to yawn, fidget, and stretch as the afternoon wears on.

She says she might choose to exercise her right to submit written questions to House prosecutors and defense lawyers later this week. But she says she would first channel any queries through her party's "appropriate people."

Echoing the views of other Democrats, Lincoln remains skeptical of the prosecutors' argument for witnesses, a controversial subject that the Senate will tackle next week. As for the final vote - when she must stand at her seat and state "guilty" or "not guilty" - Lincoln is reserving judgment.

Although she hails from the president's home state, in the House she often cast a swing vote and frequently sided against the administration. A founding member of the Blue Dog coalition of conservative Democrats in 1994, she says she will cross party lines in the Senate, too.

For Lincoln, the overarching priority is to wrap up the trial quickly but fairly, as the majority of constituents who call her office urge. She opposes any plans for the Senate to conduct other business at the same time as the trial.

"Half of [Arkansans] love him [the president] and half severely dislike him," she says, "but on impeachment the majority of people want it over."